antiHCV

antiHCV refers to antibodies against the hepatitis C virus. It is typically detected with serological tests to screen for prior exposure to HCV. A positive antiHCV result indicates that a person has been infected at some point, but it does not by itself distinguish current infection from a past resolved infection or indicate immunity. A negative antiHCV result is more informative about lack of prior exposure, though in the early acute phase after infection, antibodies may not yet be detectable.

To determine current infection, an HCV RNA test (viral load) is required. If antiHCV is positive, performing an HCV RNA test establishes whether active viremia is present. While historical confirmatory tests existed, today RNA testing is the standard method to confirm active infection.

Interpretation of results should consider the clinical context. Persistent antiHCV with detectable RNA indicates chronic infection. AntiHCV does not confer immunity, and there is currently no vaccine for hepatitis C. The existence of antiHCV can persist even after the infection has cleared, so a positive antibody test alone does not indicate ongoing disease.

Limitations include false positives, particularly in low-prevalence populations, and false negatives in immunocompromised individuals or during the window period before antibodies develop. The recommended approach is a two-step process: initial antibody screening followed by RNA testing if antibodies are present, to determine current infection status.

Use of antiHCV testing includes blood donor screening, prenatal screening, and population surveillance, and it plays a key role in guiding treatment decisions. Modern therapies, notably direct-acting antivirals, can cure most chronic HCV infections when current infection is confirmed.